#include <stdio.h>

int removeData(int data[],int n){
	double temp = n;
	for(int i = 0;i < n;i++){
		temp = data[i];
		for(int j = n-1;j >= 0;j--){
            if(i != j && data[j] == data[i]) data[j] = -1;
		}
	}
	int sum = 0;
	for(int k = 0;k < n;k++){
		if(data[k] >= 0) sum++;
	}
	return sum;
}

int main(){
	int len;
	scanf("%d",&len);
	int data[len];
	for(int i = 0;i < len;i++){
		data[i] = 0;
	}
	for(int j = 0;j < len;j++){
		scanf("%d",&data[j]);
	}
	int index = removeData(data,len);
	printf("%d",index);
	return 0;
}